Alternating-current apparatus.



W. STANLEY.

- ALTEBNATING CURRENT APPARATUS.

APPLIATIOH FILED H0123, 1905.

Patented Nov. 30, 1909. fly/ 3 SHEETS-SHEET l.

` w. STANLEY.

` vAL'IEENATING CURRENT APPARATUS.

APPLICATION FILED HOV. 23. 1905.

QfflA/Q- l Paented Nov.30, 1909.

8 SHEETS-SHEET 3.

W el SSFS.'

W. STANLEY. ALTERNATING CURRENT APPARATUS.

PPLwATIoN rmzn nov. as, 1905.

- Patented NOV. 30, 1909.

8 SHEETS-SHEET 8.

UNITED sTATEs PATENT oEEIcE.

WILLIAM STANLEY. 0F GREAT BARRINGTON, MASSACHUSETTS, ASSIGNOR T0 GENERALELECTRIC COMPANY, A CORPORATION OF NEW YORK.

ALTERNATING-CURRENT APPARATUS.

Specification of Letters Patent. V:Patente-5d NOV. 30, 1909.

Application led November 23, 1905. Serial No. 288,643.

To a-ZZ lwhom 'it may concern:

Be it known that I, WILLIAM STANLEY, a citizen of the United States,residing at Great Barrington, Massachusetts, have invented certain newand useful Improvements in Alternating-Current Apparatus, of which thefollowing is a full, clear, and exact description.

My invention relates to apparatus actuated by alternating currents. Ithas been especially devised for the purpose of operating instruments forthe measurement of alternating 'currents and the power or energy whichthey convey, although it may be used for the transmission of power andother purposes.

One object of my invention relates to the provision of a motive deviceoperating upon novel torque producing principles. The operation of thisdevice is due to the torque effects developed by currents induced withinone of its members by another. It, however, does not operate, and suchtorque is not produced, in the manner heretofore known in the art. Thereactiveeffects resulting in torque in all motive devices heretoforeknown take place between the currents induced in, for example, the rotorof the device and the impressed field or fields generating them. As wellknown, this reaction is proportional to the product of the inducedcurrent, the impressed field or fields and a function of the anglebetween them.

In my device the torque produced is exerted by the reaction of theinduced current upon the field which it itself produces, and istherefore proportional to the square of such induced current, theimpressed field serving only as a means for introducing or supplying thecurrents from one member of the machine to another.

The torque producing reaction in my invention takes place between thecurrent induced in the secondary element and a magnetic'circuit of lowreluctance placed in inductive relation yto it whereby the secondarycurrent causes a strong local field to be produced and reacts upon thesame according to the law that a circuit conveying a current tends to sodispose itself as to produce a maximum field or flux. My motive device,therefore, consists essentially of a ,primary magnet inducing secondarycurrents in a closed circuit armature, and a magnet-ic circuit of lowreluctance at one side of the i primary magnet attracting thesesecondary currents.. The only function of lthe primary magnet 1s toconstantly produce a suitable value of secondary currents at the properplace in the armature. The flux produced by the primary magnet does notenter into the reactions producing torque in the device.

The advantages derived from a motive device constructed upon thisprinciple are that the torque produced is independent ofthe phaserelation of the induced current to that of the impressed field, whichrelation limits the value of torque found in motor devices of the priorart. I'Vitli this device, therefore, I may produce a torque orturningeffort when the device is at rest superior to that obtained bythe reactions taking place between phase differing fields and thesecondary currents which they produce, for the reason that I may inducesecondary currents of greater value upon or within the movable elementand obtain from them their full torque producing value. v

Because the torque developed is due to the reaction of the ,inducedcurrents upon the field which they produce, it`necessarily follows thatsuch reaction is proportional to the square of the vinduced currents incontradistinction to the reaction taking place in known induction motivedevices between an induced current and the field or fields that produceit, in which `case such reaction is in simplev proportion to the valueof the induced currents. My device, therefore, has a high torquecoefficient.

In applying my invention to devices such as alternating currentwattmeters where the torque produced should be in simple proportion tothe variations of the E. M. F. and current in the circuit, I employ twomotive devices such as above described, whose moving elements aremechanically connected together, and so arranged as to have no mutualreactive effect upon one another. It is well known that mechanicalstrains such as cause torque, developed by the reaction of forcesuponthemselves or one of their components, are proportional to thesquare of the force. Thus, a magnet attracting its armature exerts aforce u on it proportional to the square of the the torque produced bythe motive device here shown is proportional to the square of theenergizing flux. In order therefore that my device may produce a torqueproporux present, and, similarly,

tional tothe value of its energizing currents,

'the square of the sum of the a .condition necessary when 1t 1s used tomeasure the energy of an electrical circuit,

I cause two inducing magnets. to act upon two independent secondarycircuits -mechan-l icall connected together and arranged to pro uceopposing torques, and I construct the inducin member of each motordevice with two windings arranged and connected in such a manner thatthe currents traversing the windings of one member set up M. M. F.sasslsting each other, while the same currents traversing the windings ofthe' other member. cause M. M. F.s that oppose one another. As thetorques produced by the two motive devices are pro ortional to M. F.s ofthe one and the s uare of the difference of the M. M. F.s o the other,the resultant,

torque exerted on the staii' of the instrument is proportional to thedii'erence of such .squares and therefore is pro ortional to the productof the currents 1n t e two circuits. In this arrangement when asuitable` retarding force is provided'the rateof rotation isproportional to the energy in the circuit and the device becomes awattmeter. This part of my `invention does not necessarily involve theemployment ofV my attraction motive device, but is a' plicable to othertypes of motive devices w ich involve torque reactions proportional tothe square of the impressedl flux, but in any case to directly measurethe true energy of the circuit at all times, thisA part of my inventioninvolves certain features that must be included in the device. Y

In order that the torque of the meter shall be pro ortional to the trueenergy dissipated upon tlie circuity to which it is attached, it isnecessary that such torque should be proportional to the E. M. F. andcurrent in the circuit and the cosine of their phase difference, sinceAthe maximum and minimum iiuxes developed in the two motors employed aregreatest when the energizing currents are in phase; the resultant torquedue to the difference of value of their fluxes is also greatest underthese conditions. vThis condition of coincidence is that which is also`found when the energy delivered to the circuitis maximum, while on theother-hand,

^ the energy in circuit is zero when the current in the seriesenergizing);v circuit is in 'quadrature with the current in the shuntcircuit, yunder which condltion the resultant l torque of'the two motorsis also zero as there is nodifference of values of the fluxesportionality between` the torque exerte by the motor and the flow ofenergy in circuit is brought 'aboutby reason of the entire inde endenceofthe two torque reactions.A

eferring to the. drawings accompanying the specification, Figures 1 and2 represent in side elevation and lan view,- respectively, a meterembodying t e various features of my invention; Figs. 3 and 4 show 1nsidel elevation and plan view, respectively, a motor embodying myinvention. Figs. 5, 6 and 7 are diagrammatic views explanatory of someof the principles of'operatlon of my motive device.

A is a primarymagnet and B isa rotor consisting of a conducting disk,preferably 4of copper or aluminum, in inductive relation to the magnet.The magnet is-energzed by currents in the coils a and b which areconnected one in shunt to and the other in series "with the circuit. The(pole of the magnet 1s symmetrically dispose on a radius of the armaturedisk, the currents induced in the disk, arrange themselves symmetricallyabout the figure of the pole, as indicated in dotted lines in Fig. 7,1sothat there is no tendency of movement of the disk by reason of anyreaction occurrin between the induced currents and flux o the magnet A.

W represents an iron win constituting a circuit of low magnetic reuctance closed outside the armature disk laced at one side of and innon-inductive re ation to the pole of the magnet A and` closelyad'acent' to the armature disk. This member forms in e'ect an armatureorv path through which the flux produced by the secondary currents atone si e of the pole passes.

S0 far I have onl described a portion of the elements shown 1n Figs. 1and 2, because these elements involve a novel mode of operation of mylnventlon and 1n themselves constitute a motive device. This mode ofoperation may be understood b referencel to Figs. 5 to 7, which are merey explanatory diagrams.

1n Fig. 5 Ihave shown a coil C receiving current from a source ofelectricity, as for example, the battery C. This coil is embraced at oneside by a piece of iron C2.

.When current is passed through the coil C it tends to move between thelegs of the iron member C2 so as to become as nearly'symmetricaltherewith as possible and decrease the magnetic reluctance of the coilas much as possible, in accordance with the Well known law that aconductor carrying current tends to dispose itself so as to produce themaximum magnetic flux. The force acting to. move the coil isproportional to the square of the current in it.- It is immaterial tothis action whatmeans are provided to introduce the current into thecoil or whether such current isa direct current or an alternating one.Thus in Fig. 6 the same coil and iron are shown, but instead of thebattery C providing a direct current an electro-magnet Cs energized byan alternating current is shown projecting its flux through the coil.The fluxl from this magnet induces sin-alternating current in the 4coilC, which coil is in this case shown as closed at itsrends, thusconstituting a closed circuit. The same lawV of attraction applies.'l`he"coilI tends, fortl-lesam'e -reason as before, to move between'thelegs of the adjacent iron. In this case the electro-magnet in inductiverelation tothe coil() performs thesamefunction as the battery and itsconnections in Fie. 5: The coil of the magnet and the coil constitutethe'primary and secondary circuits of a transformer the latter receivingthe current by induction from vthe iirst, while the movement of the coilis brought about by the reaction of the current within itupon the lieldwhich it in the magnetic circuit @2.0i low re uctance.

Aga-in in Fig. 7, in` which the magnet disk and circuitv of lowniafrnetic reluctance of my motive device are illustrated, thealternating current in the primary coil` of. the

ment and to the attraction ofv themember of,

low magnetic reluctance.

Thus in Fig. v7` the induced currents are indicated by the.` linessymmetrically arranged with reference to the figure of the pole. The.attraction of' these currents toward the wing W rotates the diskcontinuously toward that wing, but the induced currents are beingconstantly lreproduced in the same position vrelatively to the inducingpole and Wine` W .and are'being constantly:

attracted by t e-wing.- The motor reaction is, therefore, dependententirely upon ythe reaction betweenv the induced currents. and their own.tield andthe tor ue produced is, proportional to the square o thesecurrents.

The magnet A, rotor. disk B and wing W of Figs. 1 and 2, therefore,coact in the above l manner. The energizing-coils ofthe mag-J net A arein these gures shown as com posed of the twocoils a b, the former beingin shunt to the consumption circuit, andthe latter being a coil inseries inl that circuit. These coils are super-imposed upon the samecore and so produce a single flux. y

So far as the operation of the parts thus far describedv as .a motivevdevice'l is concerned, it is immaterial Whether thel energiziug'windingis made u of such coils oronly a single coil."v In y or erthat thedevice may accurately measure-electrical energy, however, it isnecessary' Vthatl its torque be composed of components -propprtionalreroduces. x

their magnetlzmg actlons oppose one anwhich are atspectivcly to thcF..M. F.and the current in circuit, and, vthat these components -shallfurtherbc proportional to thc phase relation of the current to its IC.M. l". This I have accomplished by combiningtwo lnotivc devices such asI have so far described, arranged to -produce opposing torques and withtheir energizing circuits so arranged and connected `that the resultanttorque ot the two moti-ve devices Will be proportional to thev energyconsun'ied in the circuit.

A is a second magnet energized by the coils a and I) exactly similar tothe coils a and b on the magnet A, but the coils on magnet A are Woundor connected so that .other while the coils on magnet A are wound orconnected so thattheir magnetizing actions assist eachother.

When .the currents in the circuits a and b are in phase the fluxes inthe magnets'A and A arel respectively proportional to the arithmeticalsum and difference of these currents.. When the currents in a and Z doAnot coincide in phase the fluxes in the magnets are respectivelyproportional to the Vector sums of suchv currents in a manner wellunderstood in the art.

B is a closed circuit armature in exactly the same vinductive relationto magnet A', as is the armature B with reference to magnet .A. Y

W vis a path of low magnetic reluctance placed at the opposite side ofthe magnet A',

Vrelatively to the position occupied by the Wing W with respect tomagnet A.

The armature disks B and B are conneeted by the shaft d, carrying a wormd', l

'which may actuate any suitable counting mechanism.

E represents a permanent magnet which Vembraces the disk B in order toretard the same, as has been customary in meter devices in order thatthe speed of the rotor shall be proportional to its torque.

In order that the meter as thus constiy.tilted should accurately recordthe watt-s yor energy. consumed in the work circuit, the

.circuits in the coils a and b should be of the same. phase` whenthereis'no lag in the curl rent of the work circuit and the two torqueproducing reactions must be entirely independent of each other. Whenthis is the case the torque produced by the magnet A upon its disk isproportional to (a-{TMZ and the torque produced by the magnet A' uponits disk is equal to (zz-by. The difference between these opposingtorques is yequal to (a+b)2-(a-b)2::4.ab. l

In order that .the currents in the coils a and bshall be of the samephase when there is no lag in the work circuit I employ a circuit ofhighV ohmic resistance containing the coi-ls'a, the resistance beingintroduced elther '-.in l`the coils or in the form of an external 4resistance R inA series therewith. 'By this means the current flowingthrough the coils a can be easily made to lag less than 50 degrecsbehind the impressed E. M. F. I then cause the` current in the coils bto lag behind its impress E. M. F. by an angle'equal to the current lagin the coils a. I preferably bring this about by shunting'the coils Z)by a suitable non-inductive reslstance YS. By selecting proper valuesfor the resistances R and S in accordance with the well known lawsgoverning the action of currents in divided circuits, the same degreeofcurrent la tained. If the currents in the coils a. and b have been soadjusted that they are of the same phase when the work 'current does notlag there being no interaction between the two torque producingreactions, the torque ofthe motor 'will be, proportional Ito the energyconsumed in the work circuit whatever the power factor ma be. Thus whenlthe current in the work clrcuit lags behind its electromotive force,the magnetizing forces of the windings of the motors are respectivelyequal to the'vector sum of afl-b,

which varies with the angle 0 between the currents in the two coils, andthe vector `sum of a.-b, which also varies with that angle. The torquesproduced by the two motors individually are-proportional to the lsquares of these quantities, which squares ploy two disks because it iseasier .toavoid any such disturbing interaction. Thevfolare,respectively az-l-bz-l-Qab cos and az-l-maab cos. The resultant torque1s therefore proportional t`o the difference between these squares or tolab cos0. .Since a is proportional to the E. M. F. and b is proportionalto. the current, lab cos .1s proportional to the true energy consumed 1nthe work circuit ywhatever the power factor of that circuit'may be. Theresultant torque is therefore proportional to the real energy consumedeven when the work current lags. t

It is not necessary to employ two separate disks provided that thecurrents inducedby one magnet cannot react upon'the .other to producetorque. I prefer, however ,-toem lowing elements are therefore necessaryfor the proper measurement of the energy of alternatlng currents by 4myinvention: First-the resultant torque of the instrument must be due tothe dilference of the individual torques of two motor reactions each ofwhich is proportional to the square of the iuX produclng it. produced inthe two motor reactionsk must be respectively proportional to the sumand difference of the magnetizing currents rep-l resenting thev E. -M.F. and current to be measured. Thirdthema etizing 'l forces of theseycurrents mustV coinclde 1n phase when the power factor 'of the circuitto bev in the coils a and b caneas'ily be ob- I Second-the fluxes ementrotatab y mounted and so arranged as to receive a currentnduced lwithinit by the induction of the primary coil g. These secondary currents aresymmetrically disosed w1th reference to the poles as shown 1n thedrawings.

.Jl J are two magnetic circuits of low reluctance embracing the disk,and so placed as to receive the maximum induction from the secondary orinduced currents. These circuits are placed uponY opposite sides of theprimar inducing magnets, so as to produce assisting tor ues uponopposite sides of the disk and there y co ratein producing rotation. Thetorque delelo ed upon the disk by the reaction of the in uced currentsand the eldswhich they produce is, as before, proportional to theproduct of these two quantities, that is to say, is proportional to thesquare of the value of the secondary or induced currents. Suchadeviceisz therefore, designed to havey a ver low resistance secondary circuitin order t at the induced currents may have a maximum value and thetorque produced be as great as possible, and, therefore, the design andconstruction of this motor differ from those employed heretofore in the'art, where the reactions taking place are dependent upon the phaserelation of theinduced current to the primary or inducing fields, andwhere such phase relationshiplimits the value of the secondar currentsemployed.

Itfwil be understood that while I have illustrated and ex lained myinvention'with refereiice'to speci c embodiments thereof, I do notdesirel to be limited to any mere detailsof construction or arrangement.I believe myself to be the first to rovide a motive device, whether tobe use for meters or for other pur oses, in -which the torque isproducedfon t eattraction principle herein described, or wherein thetorque roduced is dependent upon the reaction o the induced currentsupon their own field andentirely inde 'endent of any reaction thatincludes the ux of the primary inducin ma net.. Moreover I believemyself to e t e first to have ascertained and properly Vvapated bythesquare law shall, whatever thel power factor of the circuit, accuratelymeasure the true energy consumed therein.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is 1. The combination of an alternating currentelectro-magnet, a secondary element in inductive relation thereto, and amember of low magnetic reluctance adjacent to the secondary element andin torque-producing relation thereto, said member forming a magneticcircuit closed outside the secondary element.

2. The combination of an alternating current electro-magnet, a secondaryelement in inductive relation thereto, and a member of low magneticreluctance adjacent to thesecondary element, and at one side of saidmagnet and in torque-producing relation thereto, said member forming amagnetic circuit closed outside thesecondary element.

3. The combination of an alternating current electro-magnet, a secondaryelement in inductive relation thereto, and a member of low magneticreluctance embracin said secondary element and in torque-pr ucingrelation thereto, said member forming a closed magnetic circuit outsidesaid secondary element. l

4. The combination of an alternating current electro-ma net, a secondaryelement in inductive relatlon thereto, and means for providing a closedmagnetic path outside the secondary element for a part of the magneticclrcuit of the flux produced bythe secondary currents.

5. In a wattmeter, the combination of a rotating system, electro-magnetsin inductive relation thereto, wound so as to produce uxes pro ortionalto the vector sum and vector di erence of magnetizing forcesproportional to the potential and volume of current in the work-circuit,so disposed that each magnet is independent of the other so far astorque-producing relations are concerned, and low magnetic'reluctancemembers adjacent to the system in torque-producing relation thereto andforming closed magnetic circuits around the system.

6. In a wattmeter, the combination of two disks mechanically connected,alternatingcurrent electro-magnets in inductive relation to each disk,and members of low magnetic reluctance adjacent to each disk intorqueproducing relation thereto and forming closed magnetic circuitsoutside of the disk.

7. In a wattmeter, the combination of two disks mechanically connected,electro-magnets in inductive relation to each disk, inducing in one diskcurrents varying with the sum and in the other disk varying with thedifference of magnetizing forces proportional to the potential andvolume of current in the work circuit, and members of low magneticreluctance forming a magnetic circuit closed outside of each disk and insuch relation thereto as to produce torques of opposing direction ineach disk.

WILLIAM STANLEY.

Witnesses:

JOHN O. GEMPLER, EDWIN SEGER.

